Guard for corner-cutting machines



J. T. ROBINSON ET AL GUARD FOR CORNER CUTTING MACHINES July 1, 1.924.

Patented July 1, 1924..

ldbllllffibl id l l i itif JOHN T. ROBINSON AND GEORGE E. G-O'UDING, OF BOSTON, MASSACHUSETTS, AS- SIGNORS 'IO JOHN 'i. ROBINSOIQ' COEIIPANY, OF BQSTUDT, MASSACHUSETTS, A COR- PORATION OF MASSACHUSETTS.

GUARD FOR CORNER-CUTTING MACHINES.

Application filed August 1, 1923. Serial No. 655,055.

To aZZ whom it may concern:

Be it known that we, JOHN T. RomNsoN and GEORGE E. Goonrive, citizens of the United States, residing at Boston, county of Suffolk, Commonwealth of Massachusetts, have invented a certain new and useful improvement in Guards for Corner-Cutting Machines, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to safety appliances for cutting machines, and especially for machines for cutting the corners of paper box blanks, and has for its object to provide a shielding mechanism for machines of this type which will effectively prevent injury to the hands of the operator, and which is readily attachable as a unit to an existing ma chine and as readily detachable therefrom to permit ready access to the knife as may be required, said mechanism comprising a guard adjacent the knife and interposed between the same and the operators station together with means for automatically displacing the same when the work is introduced to the machine, said guard being of such a character as to cover the knife edge but at the same time render the latter read ily visible so as to permit the operation thereof upon the work to be inspected; and said operating means being of such a character as to cause the guard to be displaced by work in troduced at any angle to an extent automatically determined by the thickness of the work, so as always to prevent the operators hand upon thework from approaching the knife too closely. i

The foregoing and other objects of the invention, together with means whereby the same may be carried into effect, will best be understood from the following description of one form. or embodiment thereof illustrated in the accompanying drawings. It will be understood, however, that the particular construction described and shown has been chosen for illustrative purposes merely, and that the invention, as defined by the claims hereunto appended, may be otherwise practised without departure from its spirit and scope.

In said drawingsz' i Fig. 1 is a front elevation, of a portion of a corner cutting machine having the invention applied thereto.

Fig. 2 is a partial side elevation thereof. Fig. 3 is a horizontal section taken substantially on the line 3-3, Figs. 1 and 2.

The invention is herein shown as applied to a corner cutter machine of standard type, said machine having a frame comprising a bed 10 and a head 11, in which is journalled a driving shaft 12 provided with a belt pulley 13. At its forward side the head 11 is formed with vertical guides 14 for a slide 15, carrying at its lower end an angular knife 16 and being reciprocated in said guides toward and from the bed by a pitman 17 connected. at one end with a crank 18 on the shaft 12, and at its opposite end with a block 19;adjustable in said slide. The bed 10 is provided with suitably arranged undercut grooves 20 by which may be clamped to said bed in suitable positions a pair of angularly disposed gauges 21 by which the box blanks may be guided over the bed 10 into proper position under the knife 16. Said box blanks, as indicated at 22 in dotted lines on Figs. 1 and 3, are usually presented to the machine in stacks to have cut therefrom corner portions indicated at 23, being properly positioned for this purpose by the gauges 21. The parts thus far referred to constitute a machine of a type well known in the art and require no further description in detail.

The shielding mechanism constituting the present invention is supported by a bar 24 secured at its ends by bolts 25 to the guides 14; respectively, whereby said bar and the parts supported thereby may be readily attached to or detached from the machine, said bar being preferably provided with open slots 26 to receive said bolts. The bar 2 1 is formed with arms 27 and 270, supporting at their ends a pair of alined vertical guides 28 and 29 in which is mounted for longitudinal movement a rod 30 having fast to its upper end a collar 31 between which and the upper guide 28 is interposed a spring 32 by which said rod is supported and the weight of the parts carried thereby counterbalanced. Fast on the rod 30 between the guides 28 and 29 is a crosshead 33 which normally rests upon the lower guide 29, through an interposed cushioning washer 34, to fix the movement of said rod. Secured to the ends of the cross head 33 are two verticalrods 35 which are longitudinally movable in guides 36 carried by arms projecting from the guide 29. At their lower ends the rods 35 carry the knife guard 37 and the operating member 38 therefor which is preferably formed integral therewith.

The knife guard 37 is shaped substantially to conform to the shape of the angular knife 16 and is disposed immediately in front thereof. Said guard normally occupies a position relatively close to the bed 10, as shown in Figs. 1 and 2, and, as hereinafter described, is raised by the introduction of the work into the machine to a Joint substantially level with the upper surface thereof so as to shield the edge of the knife 16 when the latter descends upon said work. Inorder, however, to render the edge of said knife readily visible so as to determine the proper engagement thereof with the work, said guard 37 is made in the form of a comb with teeth disposed downwardly or toward the edge of the knife, which is readily visible between said teeth, th latter, however, being spaced sufficiently closely to prevent the introduction of the fingers of the operator therebetween.

The operating member 88, which is engaged by the work to lift the guard 37, is formed with inclined work engaging surfaces at different sides so as to be raised by work pressed to the knife from different directions. It is customary in presenting a stack of box blanks to a machine of this type to move said stack into engagement with one of the gauges 21 and thereafter to slide the same along said gauge into engagement with the other. The work engaging member 38 is therefore formed with inclined work engaging surfaces at its sides in order to cause the same to be raised by work presented at either angle, and is also preferably formed with a similar surface di rectly in front for engagement by work introduced into the machine from this direction.

The lower end of the. member 38 is preferably substantially level with or slightly below the lower edge of the guard 37, so that, as said operating member is lifted to an extent determined by the height of the stack of blanks, and thereafter rests upon the top thereof, the guard 37 will also be raised to a point substantially flush with the top of the work, so as to prevent the operators hand, which rests upon the top of the stack of blanks, from approaching the path of movement of the knife.

Having thus described our invention, we claim:

1. The combination with mechanism for cutting the corners of box blanks, said mechanism including a movable knife, of mechanism for. shielding said knife to prevent injury to the operator, said shielding mechanism being attachable to and removable from said cutting mechanism as a unit and comprising a knife guard, means for movably supporting said guard, and means engaged by the work upon introduction of the latter into the machine for moving said guar 2. The combination with a knife, a slide by which said knife is carried, vertical guides for said slide, and means for reciprocating said slide in said guides, of a bar detachably secured at its ends to said guides, a guard for said knife movably supported by said bar, and an. operating member ongaged by the work, upon. introduction of the latter into the machine, to move said guard in said bar.

3. A shielding mechanism for corner cutting machines comprising a bar, means for detachably securing the ends of said bar to the frame of said machine, vertical guides on said bar, a rod longitudinally slidable in said guides, a knife guard carried by said rod, and an operating member carried by said rod and engaged by the work upon its introduction into the machine.

4. In a corner cutting machine, the combination with a knife, of a guard normally interposed between said knife and the operators station, and means engaged by the work, upon introduction of the latter into the machine, to displace said guard.

5. In a machine for cutting the corners of box blanks, the combination with a knife, of a guard normally interposed between said knife and the operators station, said guard being constructed and arranged to cover but render visible the edge of said knife prior to the cutting operation, and means engaged by the work upon introduction of the lati er into the mac line, to displace said guard.

6. A shielding mechanism for corner cutting machines comprising a knife guard, means for movably supporting said guard, and means engaged by the work, upon introduction of the latter into the machine, to displace said guard.

7. A shielding mechanism for corner cutting machines comprising a knife guard, means for supporting the same for vertical movement, and an operating membe ongaged by the work, upon introduction of the latter into the machine, to lift said guard.

8. A shielding mechanism for corner cutting machines comprising a knife guard, means for supporting th same for vertical movement, means for counterbalancing said guard, and an operating member engaged by the work, upon introduction of the latter into the machine, to lift said guard.

9. A shielding mechanism for corner cutting machines comprising a knife guard, a rod for supporting the same, vertical guides in which said rod is longitudinally movable, a collar on said rod, a spring interposed between said collar and one of said guides for supporting said rod and guard, and an 0perating member engaged by the work, upon introduction of the latter into the machine, to lift said guard.

10. A shielding mechanism for corner cutting machines comprising a knife guard, a rod for supporting the same, vertical guides in which said rod is longitudinally movable,

duction of the latter into the machine, to

lift said guard.

11. A shielding mechanism for corner cutting machines comprising a knife guard, means for supporting the same for vertical movement, and an operating member engaged by the work, upon introduction of the latter into the machine, to lift said guard to a point substantially level with the top of the work.

12. A shielding mechanism for corner cutting machines comprising a knife guard, means for supporting the same for vertical movement, and a work engaging member carried by said guard and having its lower end substantially level with the lower edge of said guard, said member having an inclined surface engaged by the work, upon introduction of the latter into the machine, to lift said guard.

13. A shielding mechanism for corner cutting machines comprising a support, vertical guides on said support, a rod longitudi' nally movable in said guides, a spring for supporting said rod, a cross-head on said rod, vertical rods carried by the ends of said cross-head, guides on said support for said last named rods, and a knife guard and a work engaging operating member therefor carried by said last named rods.

14. A shielding mechanism for corner cutting machines comprising a knife guard, means for supporting the same for vertical movement, and an operating member connected with said guard to lift the same, said member having inclined work engaging surfaces at different sides, whereby it may be raised by work introduced into the machine from different directions.

15. The combination with a corner cutting machine comprising an angular knife, a bed, means for reciprocating said knife toward and from said bed, and angularly disposed gauges on said bed for guiding the work into position under said knife, ofmechanism for shielding said knife comprising a guard shaped substantially to conform to the shape of said knife and disposed adjacent thereto, means for supporting said guard for vertical movement, and an operating member connected with said guard to lift the same, said member having inclined work engaging surfaces at different sides, whereby it may be raised by work presented to said knife from different directions between said gauges.

In testimony whereof we affix our signatures.

JOHN T. ROBINSON.- GEORGE E. GOODING. 

